Good question! And a hard one to answer.
The DMC-1880 is the prior generation, top-of-the-line controller. I have about 50 of the 18x0 series cards running in the field with no problems. But..... You need cables and breakout boards for the card so that can add another $300-$500 to the overall cost depending on what is available on the used market. It is possible that the DMC-1880 comes with cables and breakouts, I have seen them sold that way on Ebay. Good documentation is available for download from the Galil website, and they have a user forum on the website also. Programming is simple using any text editor or the free Galil software, and Galil has a very good, free, API for use with Microsoft .net platform that works with Win7 - 10, they also have an API for the WinXP platform programmable with C++ or VB6.
I haven't used the Dynomotion products, but I know they are well regarded and have overall performance that is close to the Galil products. As I understand they are field programmable to customize their functions. Tom Kerekes would be the person to answer your questions about their products.
Bottom line is I can't really give you a definitive answer. I would lean towards the Galil, but only because there would be no learning curve for me, and I already have software modules written that I can drop into any control program and user interface as needed.